1. Field of Technology
The current invention is in the field of digital communications. More specifically, the present invention is noise and interference tolerant bit communication system over a balanced (Nx2)-channel transmission medium.
2. Background of the Invention
In communication systems, Noise is random energy that interferes with the information signal during demodulation at the receiver. Noise may be defined as any unwanted introduction of energy tending to interfere with the proper reception and reproduction of a modulated transmitted signal. In a fundamental communication system receiver, noise may produce errors at receiver output. Noise may limit the speed and range of communication systems.
Electrical noise in specific; may be any undesirable energy that falls within the passband of the signal. There are two general categories of noise: Correlated Noise—implies relationship between the signal and the noise, exist only when signal is present, and Uncorrelated Noise—present at all time, whether there is a signal or not.
Although not limited to, Correlated Noise may be classified as follows: i) INTERFERENCE: An unwanted energy correlated with the main signal. Interference, at a certain level, will corrupt the information signal. ii) SWITCHING NOISE: Generated by the operation of the very basic electrical, electronic and transmission devices which form a communication system. The on/off switching of communication devices, may introduce correlated noise.
Whereas Uncorrelated Noise may be classified (yet not limited to) as follows:
ATMOSPHERIC NOISE: Caused by lightning discharges in thunderstorms and other natural electric disturbances occurring in the atmosphere, consisting of spurious radio signal with components distributed over a wide range of frequencies. It propagates over the earth in the same way as ordinary radio waves of the same frequencies, and becomes less severe at frequencies above 30 MHz because: The higher frequencies are limited to line-of-sight propagation. Nature of the mechanism generating this noise is such that very little of it is created in the Very High Frequency (VHF) range and above.
EXTRATERRESTRIAL NOISE/SOLAR NOISE: A constant noise radiation from the sun radiates over a very broad frequency spectrum.
COSMIC NOISE: Stars radiate RF noise in the same manner of sun. The noise received is called thermal noise and distributed fairly uniformly over the entire sky.
INDUSTRIAL NOISE: Is between 1 to 600 MHz, the intensity noise made by humans easily outstrips that created by any other source to the receiver (Sources such as automobile, aircraft, electric motors and other heavy machine). The nature of industrial noise is so variable that it is difficult to analyze.
SHOT NOISE: Caused by the random arrival of carriers at the output element of an electronic device. First observed in the anode current of a vacuum-tube amplifier, the current carriers are not moving in continuous steady flow, randomly varying and superimposed onto any signal present. This type of noise is sometimes called transistor noise.
THERMAL NOISE: Is associated with the rapid and random movement of electrons within a conductor due to thermal agitation and present in all electronic component and communications systems, and referred to as white noise, which is a form of additive noise, that cannot be eliminated. It increases in intensity with the number of devices in a circuit.
Thermal noise power is proportional to the product of bandwidth and temperature. Mathematically, noise power is N=KTB N=noise power, K=Boltzmann's constant (1.38×10^−23 J/K), B=bandwidth, T=absolute temperature (Kelvin) (17° C. or 290K).
In general, since demodulation is always a function of the received signal and the noise, higher modulated data transmission speeds require higher Signal-to-Noise-Ratio (SNR) values at receiver end. Thus, as one major factor, higher data speeds are mainly impeded by higher noise across the communication channel between transmitter and a receiver. For high speed communication, high SNR ratios are required such that data can be transmitted while maintaining the data receiver to function at acceptable levels of Bit Error Rate (BER) during demodulation.